Small intestinal atresia occurring in twins is extremely rare. The aims of this study are to report a case of identical twins with different types of jejunal atresia, to review six other pairs of twins, and discuss the etiology. Our case was the seventh in which both twins were diagnosed to have jejuno-ileal atresia. Furthermore, they are also only the sixth and seventh patients known to survive. All the other published cases involved identical twins except one. Three pairs had different types of atresia and four pairs did not have any other anomalies. In addition, to date there have been no further indications of any other members of these families being affected with intestinal atresia. Therefore, we conclude that most such cases might be due to environmental influences during gestation.